Zone Players are the heart of the Sonos system. You place them anywhere in your house where you want to hear music. Add the company's CR100, a handheld controller designed a bit like an iPod, and you can play music in all the zones of your house--either the same music everywhere or different tracks in different rooms. The various pieces of Sonos hardware communicate among themselves through a wireless mesh network that the devices automatically set up. A basic two-zone system costs $999.

(Earlier this year, Logitech released a less expensive alternative, called ; a comparable two-zone setup with the Duet costs $550. But its streaming devices don't include an amplifier--they have to be connected to your stereo or to powered speakers.)

The new Zone Player 120 is 35 percent smaller than the ZP100, thanks to an extruded aluminum case that acts as a heat sink. (Sonos doesn't use any fans to cool inside; I didn't feel the unit get hot to the touch, however.)

The company also claims that it has doubled the wireless range in the ZP120. Reliably testing wireless range is difficult because of interference from other wireless sources or because of obstruction by walls and windows, but I did find that I could use the system in the far reaches of my house, something that was occasionally a problem with the older Sonos hardware.

The ZP120 also boasts more audio power, 55 watts per channel, up from 50 watts per channel in the older version.